• The Korean Journal of Applied Statistics
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• v.32 no.5
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• pp.763-782
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• 2019

This paper proposes a probabilistic document ranking model incorporating term dependencies. Document ranking is a fundamental information retrieval task. The task is to sort documents in a collection according to the relevance to the user query (Qin et al., Information Retrieval Journal, 13, 346-374, 2010). A probabilistic model is a model for computing the conditional probability of the relevance of each document given query. Most of the widely used models assume the term independence because it is challenging to compute the joint probabilities of multiple terms. Words in natural language texts are obviously highly correlated. In this paper, we assume a multinomial distribution model to calculate the relevance probability of a document by considering the dependency structure of words, and propose an information retrieval model to rank a document by estimating the probability with the maximum entropy method. The results of the ranking simulation experiment in various multinomial situations show better retrieval results than a model that assumes the independence of words. The results of document ranking experiments using real-world datasets LETOR OHSUMED also show better retrieval results.

• Journal of the Korean Ceramic Society
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• v.45 no.7
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• pp.411-417
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• 2008

Aerosol Deposition Method (ADM) is a novel technique to grow ceramic thick films with high density and nano-crystal structure at room temperature. $^{1,2)}$ For these unique advantages of ADM, it would be applied to the fabrication process of 3-D integration ceramic modules effectively. However, it is critical to control the properties of starting powders, because a film formation through ADM is achieved by impaction and consolidation of starting powders on the substrates. We fabricated alumina thick films by ADM for the application to integral substrates for RF modules. When the as-received alumina powders were used as a starting material without any treatments, it was observed that the dielectric properties of as-deposited alumina films, such as relative permittivity and loss tangent, showed high dependency on the frequency. In this study, some techniques of powder pre-treatments to improve the dielectric properties of alumina thick films will be shown and the effects of starting powders on the properties of AD films will be discussed.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.2
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• pp.88-92
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• 2020

Thermal effects in bulk and SOI FinFETs are briefly reviewed herein. Different techniques to measure these thermal effects are studied in detail. Self-heating effects show a strong dependency on geometrical parameters of the device, thereby affecting the reliability and performance of FinFETs. Mobility degradation leads to 7% higher current in bulk FinFETs than in SOI FinFETs. The lower thermal conductivity of SiO₂ and higher current densities due to a reduction in device dimensions are the potential reasons behind this degradation. A comparison of both bulk and SOI FinFETs shows that the thermal effects are more dominant in bulk FinFETs as they dissipate more heat because of their lower lattice temperature. However, these thermal effects can be minimized by integrating 2D materials along with high thermal conductive dielectrics into the FinFET device structure.

• Earthquakes and Structures
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• v.4 no.5
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• pp.451-470
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• 2013

It generally accepted that most building structures shall exhibit a nonlinear response when subjected to medium-high intensity earthquakes. It is currently known, however, that this phenomenon is not properly modelled in the majority of cases, especially at the design stage, where only simple linear methods have effectively been used. Recently, as a result of the exponential progress of computational tools, nonlinear modelling and analysis have gradually been brought to a more promising level. A wide range of modelling alternatives developed over the years is hence at the designer's disposal for the seismic design and assessment of engineering structures. The objective of the study presented herein is to test some of these models in an existing structure, and observe their performance in nonlinear static and dynamic analyses. This evaluation is done by the use of two of a known range of advanced computer programs: SAP2000 and SeismoStruct. The different models will focus on the element flexural mechanism with both lumped and distributed plasticity element models. In order to appraise the reliability and feasibility of each alternative, the programs capabilities and the amount of labour and time required for modelling and performing the analyses are also discussed. The results obtained show the difficulties that may be met, not only in performing nonlinear analyses, but also on their dependency on both the chosen nonlinear structural models and the adopted computer programs. It is then suggested that these procedures should only be used by experienced designers, provided that they are aware of these difficulties and with a critical stance towards the result of the analyses.

• Korean Journal of Organic Agriculture
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• v.20 no.3
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• pp.267-282
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• 2012

In this study, RPS system, one of the renewable energy support systems, is utilized for economic analysis of solar generation equipment and the fuel cost savings plan for controlled horticulture farms with high fuel-cost dependency and facility applicability were evaluated. On the exterior of the upper layer of glass greenhouse (9917$m^2$) of controlled horticulture farms using bunker C oil, half of the area (4958$m^2$) was utilized for theoretical installation and operation of 450kW-level solar power generator, and as the result, first, the effect of investment cost only of solar generation system was found to be quite excellent, but it was analyzed that there were limits to saving the fuel costs of the controlled horticulture farms. Second, when geothermal system was first introduced in the farm and solar system was additionally introduced, it was analyzed that the effect of introducing solar system was excellent. In order to apply such effects to the sites of farming, partial supplementation of RPS system which is being uniformly applied regardless of the purpose of renewable energy is necessary. When the subject of use directly install facilities where it is directly connected to national added-value such as food security created by the farming industry, it is necessary to introduce appropriate system that corresponds to such. Moreover, it was studied that the quick development of demonstrative complex that can practically evaluate the applicability of renewable energy in farming industry and interest and preparation of related institutions in financial support structure for its site application would lead to success.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.21-21
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• 2011

A series of Quasi-Elastic Neutron Scattering (QENS) experiments helps us to understand the single-particle (hydrogen atom) dynamics of a globular protein and its hydration water and strong coupling between them. We also performed Molecular Dynamics (MD) simulations on a realistic model of the hydrated hen-egg Lysozyme powder having two proteins in the periodic box. We found the existence of a Fragile-to-Strong dynamic Crossover (FSC) phenomenon in hydration water around a protein occurring at TL=$225{\pm}5K$ by analyzing Intermediate Scattering Function (ISF). On lowering of the temperature toward FSC, the structure of hydration water makes a transition from predominantly the High Density Liquid (HDL) form, a more fluid state, to predominantly the Low Density Liquid (LDL) form, a less fluid state, derived from the existence of a liquid?liquid critical point at an elevated pressure. We showed experimentally and confirmed theoretically that this sudden switch in the mobility of the hydration water around a protein triggers the dynamic transition (so-called glass transition) of the protein, at a temperature TD=220 K. Mean Square Displacement (MSD) is the important factor to show that the FSC is the key to the strong coupling between a protein and its hydration water by suggesting TL${\fallingdotseq}$TD. MD simulations with TIP4P force field for water were performed to understand hydration level dependency of the FSC temperature. We added water molecules to increase hydration level of the protein hydration water, from 0.30, 0.45, 0.60 and 1.00 (1.00 is the bulk water). These confirm the existence of the FSC and the hydration level dependence of the FSC temperature: FSC temperature is decreased upon increasing hydration level. We compared the hydration water around Lysozyme, B-DNA and RNA. Similarity among those suggests that the FSC and this coupling be universal for globular proteins, biopolymers.

• Journal of KIISE:Computing Practices and Letters
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• v.10 no.2
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• pp.156-173
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• 2004

Business process should support the execution of collaboration process with agility and flexibility through the integration of enterprise inner or outer applications and human resources from the collaborative workflow view. Although the dependency of enterprise activities to the automated system has been increasing, human role is as important as ever. In the workflow modelling this human role is emphasized and the structure to control human error by analysing decision-making itself is needed. Also, through the collaboration of activities agile and effective communication should be constructed, eventually by the combination and coordination of activities to the aimed process the product quality should be improved. This paper classifies human errors can be occurred in collaborative workflow by applying GEMS(Generic Error Modelling System) to control them, and suggests human error control method through hybrid based modelling as well. On this base collaborative workflow modeling tool is designed and implemented. Using this modelling methodology it is possible to workflow modeling could be supported considering human characteristics has a tendency of human error to be controlled.

• Journal of Science and Technology Studies
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• v.8 no.1
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• pp.1-28
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• 2008

This study investigates the characteristics and implications of the newly emerging socially-oriented innovation policy. The socially-oriented innovation policy has systemic views on the evolution of socio-technical system and innovation policy. It's ultimate goal is the transition toward sustainable socio-technical system and it takes "strategic niche management" approach for the transition policy. The governance structure of the policy is more open to the public actors, such as social service organizations and public institutes. As a case study, "the Technology-based Policy for the Enhancement of Quality of Life", which is the first comprehensive socially-oriented policy of Korea, is examined and it is suggested that the policy has some limitations because of the path dependency of targeting-oriented and catching-up style innovation policy of Korea.

• Journal of Korean Academy of Nursing
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• v.49 no.6
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• pp.724-735
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• 2019

Purpose: This study was conducted to investigate relationship between delirium, risk factors on delirium, and patient prognosis based on Donabedian's structure-process-outcome model. Methods: This study utilized a path analysis design. We extracted data from the electronic medical records containing delirium screening data. Each five hundred data in a delirium and a non-delirium group were randomly selected from electronic medical records of medical and surgical intensive care patients. Data were analyzed using SPSS 20 and AMOS 24. Results: In the final model, admission via emergency department (Β=.06, p=.019), age over 65 years (Β=.11, p=.001), unconsciousness (Β=.18, p=.001), dependent activities (Β=.12, p=.001), abnormal vital signs (Β=.12, p=.001), pressure ulcer risk (Β=.12, p=.001), enteral nutrition (Β=.12, p=.001), and use of restraint (Β=.30, p=.001) directly affecting delirium accounted for 56.0% of delirium cases. Delirium had a direct effect on hospital mortality (Β=.06, p=.038), hospital length of stay (Β=5.06, p=.010), and discharge to another facility (not home) (Β=.12, p=.001), also risk factors on delirium indirectly affected patient prognosis through delirium. Conclusion: The use of interventions to reduce delirium may improve patient prognosis. To improve the dependency activities and risk of pressure ulcers that directly affect delirium, early ambulation is encouraged, and treatment and nursing interventions to remove the ventilator and drainage tube quickly must be provided to minimize the application of restraint. Further, delirium can be prevented and patient prognosis improved through continuous intervention to stimulate cognitive awareness and monitoring of the onset of delirium. This study also discussed the effects of delirium intervention on the prognosis of patients with delirium and future research in this area.

• Journal of the Earthquake Engineering Society of Korea
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• v.9 no.2 s.42
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• pp.47-58
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• 2005

Dynamic response analysis in time dimain is conducted for floating bridges with discrete pontoons subject to spatial variation of ground motions. The Spatial variation of ground motions is considered with the coherency function model which represents wave passage, incoherence and local site effects. The superstructure of the bridge is represented by space frame and elastic catenary cable elements, the abutment us modelde with the spring element of FHWA guideline for considering soil structure interaction and the concept of retardation function is utilized to consider the frequency dependency of the hydrodynamic coefficients which are obtainde by boundary element method. multiple support excitations considering the spatial variation. The noticeable amplification of the response can be shown when the spatial variation of ground motions is incorporated in the anallysis of floating bridges.